A known electrophotographic image forming apparatus includes an image carrying member configured to carry an electrostatic latent image and a developing agent carrying member configured to carry a developing agent and supply the developing agent to an electrostatic latent image on the image carrying member.
For example, a known laser printer includes a frame holding a photosensitive drum and a developing unit supporting a developing roller. The developing unit is configured to be attached to and removed from the frame.
In the laser printer, protrusions protrude outward in an axial direction of the developing roller from a storage case of the developing unit. As the protrusions are pressed, the developing unit is pressed toward the photosensitive drum.